Indiana State Beauty Practice Exam

Which of the following is a common ingredient in sunscreen?

1. Glycolic acid

2. Titanium dioxide

3. Petrolatum

4. Castor oil

The correct answer is: Titanium dioxide

Titanium dioxide is a common ingredient in sunscreen due to its effective ability to block ultraviolet (UV) rays from the sun. As a physical (or mineral) sunscreen agent, it works by sitting on the surface of the skin and reflecting or scattering UV radiation, thereby protecting the skin from the harmful effects of sun exposure, such as sunburn and increased risk of skin cancer. In addition to its protective qualities, titanium dioxide is often preferred in formulations for sensitive skin because it is less likely to cause irritation compared to some chemical sunscreen agents. Its ability to provide broad-spectrum protection makes it a staple in many sunscreen products. The other ingredients listed, while they may have their own relevant uses in skincare, do not serve the primary purpose of UV protection as titanium dioxide does. Glycolic acid is predominantly used for chemical exfoliation, petrolatum is primarily utilized for its moisturizing and occlusive properties, and castor oil functions mainly as a lubricant and emollient. Therefore, titanium dioxide distinctly stands out as a key component specifically for sunscreens.